L-cysteine stimulates hydrogen sulfide synthesis in myocardium associated with attenuation of ischemia-reperfusion injury

Abstract

Hydrogen sulfide (H2S) is a biological mediator produced by enzyme-regulated pathways from L-cysteine, which is a substrate for cystathionine-γ-lyase (CSE). In myocardium, endogenously and exogenously administered H2S has been shown to protect against ischemia-reperfusion injury. We hypothesized that L-cysteine exerts its protective action through stimulation of H2S production. Rat isolated hearts were Langendorff-perfused and underwent 35-minute regional ischemia and 120-minute reperfusion. L-cysteine perfusion from 10 minutes before ischemia until 10 minutes after reperfusion limited infarct size in a concentration-dependent manner, maximal at 1 mmol/L (control 36.4% ± 2.4% vs L-cysteine 24.3% ± 3.4%, P